Vitamin E is not a single substance, but a group of substances that include four types of tocopherols (alpha, beta, gamma and delta). In humans, alpha-tocopherol is the most effective one. Vitamin E supplements usually contain only alpha-tocopherol. Vitamin E can not be produced by the body so we have to get them from food. The main sources of vitamin E are vegetables, fruits and grains such as corn, papaya, avocado, beans and cooking oil. Vitamin E can be damaged by heating and storage. The food processing industry, often adds synthetic vitamin E into foods to compensate for losses.
The function of vitamin E in the body
Vitamin E has several functions in the body. As vitamin C and A, vitamin E is a natural antioxidant works to neutralize free radicals, aggressive molecules that damage the body cells. The number of free radicals can be rise by stress, smoking or exposure to sunlight. Because free radicals increase the risk of diseases such as cancer, heart disease or cataracts, antioxidants can reduce the risk of this disease to a certain extent. Vitamin E also supports the body’s defenses and protect against atherosclerosis (hardening of arteries).
The need for vitamin E
Doses of vitamin E is expressed in milligrams and IU (International Unit) which is a special unit for vitamins and other biologically active substances. IU definition is different for each vitamin. There is no equivalence between the different vitamins and even between species within a group of vitamins. For instance, one IU of vitamin E does not have the same amount with one IU of vitamin A.
One IU of natural vitamin E have different numbers with one IU of synthetic vitamin E. We just need vitamin E in very small amounts in each day, only 14 milligrams for men and 12 milligrams for adult women. Pregnant and nursing women need a little more. The need for vitamin E also increased in people who smoke, stress, heart disease and low immunity.The most common amount recommended for vitamin E supplementation in adults is 400 to 800 IU per day.
However, some experts advise to just take 100 to 200 IU per day, because the long-term study showed that there was no additional benefit from the intake that exceeds that amount.
Vitamin E deficiency
Vitamin E deficiency is rare. Most people get enough vitamin E through their diet. Vitamin E is a fat soluble vitamin, which means that our bodies can store this vitamin in the liver as a reserve. As long as you eat a variety of foods such as vegetables, fruits, grains and moderate amounts of unsaturated fats from vegetable oils, you get enough vitamin E for every day needs.Vitamin E supplementation is not required. Our bodies will take vitamin E from reserve in the liver if we get less intake of vitamin E from food. We will have shortage of vitamin E, if we eat foods low in vitamin E continually in a long time.
Vitamin E deficiency can also be caused by impaired absorption in the intestine (eg, malabsorption of fat) and other conditions. People with a genetic defect in the protein that transfers vitamin E, called thrombotic thrombocytopenic purpura (TTP) had severe vitamin E deficiency, characterized by low blood pressure and progressive neurological disorder.
Older people with diabetes also tend to show a significant reduction of vitamin E in their blood serum. Vitamin E deficiency can lead to severe symptoms such as poor in concentration, muscle weakness, and increased susceptibility to infection.
Overdose of vitamin E
As a fat-soluble vitamin, vitamin E can accumulate in the body, making it more risky than water-soluble vitamins. High doses of vitamin E (especially if taken over the long term) can cause several problems, such as fatigue, weakness, headache, nausea, diarrhea, abdominal pain, bloating, and increased risk of bleeding